rebase to d4f03186c8986ffde34d06fe74a99aab08f7ee0b
Add ERR_PTR convetion patches
add patch remove-a-duplicate-call-in-ext4_init_new_dir
add patch use-ext4_update_i_disksize-instead-of-opencoded-ones
add patch use-ext4_ext_next_allocated_block-instead-of-mext_next_extent
add patch refactor-ext4_move_extents-code-base
add patch ext4_swap_extents-error-handling
checkpoint patches directory -- lots of new patches
add patch enable-block-validity-by-default
add patch fix-comments-about-get_blocks
add patch improve-extents-status-tree-trace-point
add patch track-extent-status-tree-shrinker-delay-stats
drop warning by rearranging order of an inline function
add ext4_state_delalloc cleanup patches
add jbd2 checkpoint optimizations
add jan kara's reviewed-by
add patch renumber-ext4_ex-flags
Move get_bh outside of the spinlock critical region
respond to Jan's review comments
save the extent_status patches in the unstable portion of the tree